Historians usually date the Baroque era from about 1600 to 1750 and the Classical era from about 1750 to 1820. The labels came later and the borders are blurry, but the change in sound is easy to hear: from music of rich, continuous motion to music of clear phrases, balanced like well made sentences.

Opera and the Baroque

Around 1600 a circle of scholars and musicians in Florence, trying to revive what they imagined ancient Greek drama had sounded like, developed a new kind of singing: a solo voice declaiming words over simple chords. From this came opera, a staged drama in which the story is sung, with orchestra, costumes and scenery. Jacopo Peri's Euridice (1600) is the earliest opera whose music survives complete, and Claudio Monteverdi's Orfeo (1607) is the earliest still widely performed. Public opera houses opened in Venice in 1637, and opera became Europe's most glamorous entertainment.

Baroque music rests on basso continuo: a bass line played throughout, with a keyboard or lute filling in chords above it. On top, composers placed long, unfolding melodies with lavish ornament. A Baroque movement usually holds one mood from start to finish.

The concerto set a soloist or small group against the full orchestra, trading contrasts of loud and soft, few and many. Antonio Vivaldi, a priest who taught at a Venice orphanage whose all girl orchestra became famous, wrote hundreds of concertos, including The Four Seasons (published 1725), which depicts birdsong, storms and a shivering winter.

Bach and Handel

Johann Sebastian Bach (1685 to 1750) spent most of his career as a church musician, from 1723 in Leipzig, where in his first years he produced a new cantata nearly every week. He was the great master of the fugue, a polyphonic piece in which a short theme enters in each voice in turn and is then developed. His Well Tempered Clavier, with preludes and fugues in all twenty four major and minor keys, showed what a keyboard tuned to make every key usable could do. After his death Bach was half forgotten until a revival in the 1800s.

George Frideric Handel, born the same year, made his career in London, first with Italian operas and then with English oratorios, large sacred dramas for chorus and soloists performed without staging. Messiah was first performed in Dublin in 1742 at a charity concert whose proceeds helped prisoners and hospitals.

The Classical style

By the mid 1700s, taste turned toward simplicity. Classical style favors clear, balanced phrases, a tune over simple accompaniment, and sudden contrasts of mood within a single movement. The orchestra settled into a standard group of strings, woodwinds, horns, trumpets and timpani, and the harpsichord faded as the new piano, which could play loud or soft by touch, took over.

The key Classical structure is sonata form, with three main sections: exposition, development and recapitulation. The exposition presents contrasting themes in two keys, setting up tension. The development breaks those themes apart and wanders through other keys. The recapitulation brings the themes back in the home key, resolving the tension. Sonata form shaped the first movements of most symphonies, string quartets and sonatas for a century.

Patrons and the public

Musicians depended on patrons. Haydn spent nearly three decades employed by the Esterházy princes, wearing their livery like other household servants, and there developed the symphony and the string quartet. Mozart (1756 to 1791) broke with his employer, the Archbishop of Salzburg, in 1781 and tried to live as a freelancer in Vienna on concerts, teaching, commissions and sales. It was a precarious life. Over time, public concerts and music publishing let composers earn from audiences rather than only from courts and churches.

That world included Joseph Bologne, Chevalier de Saint-Georges (1745 to 1799), born in Guadeloupe to a French planter and an enslaved African woman. He became a celebrated violinist, fencer and composer in Paris, led one of its finest orchestras, and later commanded a regiment of men of color in the Revolutionary army. His career shows both what talent could win and how race limited it: a plan to make him director of the Paris Opéra reportedly collapsed after singers objected to taking orders from a man of mixed race.

Worked example: the Farewell Symphony

In 1772 Prince Nikolaus Esterházy kept his musicians at his remote summer palace longer than usual, and most had left their families at home. Haydn answered with his Symphony No. 45. Its finale begins fast, as expected, then breaks into a slow section in which the players finish their parts one after another, put out the candles on their stands and leave. At the end only two violins remain.

The prince, the story goes, took the hint, and the court left for home soon after. The story comes from Haydn's early biographers, who heard it from him in old age, so details may be polished, but the score really is built this way.

Think about what it shows. Haydn was a servant who could not simply demand leave. He made his request in the language his employer valued, with wit rather than complaint. It also shows how form can carry meaning: by abandoning the expected ending, Haydn made the shape of the piece itself the message.